In this work, the supercritical antisolvent (SAS) process was used to coprecipitate Eudragit L100-55 (EUD) with diclofenac (DICLO) and theophylline (THEOP), with the aim of obtaining composite microparticles with a prolonged drug release for oral delivery. Working at the optimized conditions in terms of pressure and overall concentration in the liquid solution (10.0 MPa and 50 mg/mL), microparticles of EUD/DICLO 20/1 and 10/1 w/w were produced with a mean size of 2.92 µm and 1.53 µm, respectively. For the system EUD/THEOP, well-defined spherical microspheres with a mean diameter ranging from 3.75 µm and 5.93 µm were produced at 12.0 MPa. The produced composite systems were characterized by various techniques, such as scanning electron microscopy, differential scanning calorimetry, X-ray microanalysis, FT-IR and UV-vis spectroscopy. Dissolution studies showed the potential of EUD to prolong the drug release, significantly, up to a few days.
Keywords: SAS coprecipitation; controlled drug delivery systems; eudragit; microparticles; supercritical carbon dioxide.